MILWAUKEE — Paul Ryan's friends and opponents in Wisconsin and his hometown of Janesville are nearly unanimous in describing the congressman as likable and intelligent. The common ground ends when it comes to his politics.

Democrats and Republicans alike say Ryan is serious, hard-working and has a solid grasp of budget issues. They agree he is cordial and charismatic and that he relates well to voters.

But there's stark disagreement about his signature effort, a conservative budget plan to remake Medicare and cut trillions in federal spending. He is also emerging as a leading intellectual force in the conservative opposition to President Barack Obama, and has given little ground in negotiations over the federal budget and the deficit.

Those actions have made him a darling of conservative Republicans and tea party members, who say they're elated that Mitt Romney has selected Ryan as his running mate.

Ryan "brings a record of leadership and personal integrity that we need in Washington," said U.S. Sen. Ron Johnson, a Wisconsin Republican. "Nobody understands the federal budget better than Paul, or has worked harder to develop and offer real solutions to the fiscal challenges facing America."

Ryan, 42, is chairman of the House Budget Committee and primary author of conservative tax-and-spending blueprints that the tea party-infused Republican majority approved despite Democratic opposition in 2011 and again in 2012.

He envisions transforming Medicare into a program in which seniors would receive government checks that they could use to purchase health insurance. Under the current program, the government directly pays doctors, hospitals and other health care providers.

Peter Barca, the Democratic minority leader in the Wisconsin state Assembly, previously represented the same congressional district that Ryan does now.

"He's an articulate, good-looking guy," Barca said of Ryan. "He'd talk like a moderate in Wisconsin but it wasn't until his last budget that people saw how extreme his views are."

Despite being a vice presidential candidate, Ryan isn't dropping his bid for his eighth congressional term. Wisconsin law generally prevents candidates from seeking two offices at the same time, but provides an exception when one of the offices is either president or vice president.

If Ryan prevails in both races, the vice presidency would void his congressional win. A special election would be held to fill the congressional vacancy.

Even though Democrats may disagree with Ryan's policies, they agree their dealings with him as a congressman are almost always cordial. However, they said being vice president is about more than just being a nice guy.

U.S. Rep. Tammy Baldwin, who is giving up her seat to run for the U.S. Senate, said she considers Ryan a friend. But she said Romney and Ryan would support tax cuts for millionaires at the expense of providing senior care and keeping college costs down.

Some Democrats were more tempered in their assessment of Ryan's policies.

State Sen. Tim Cullen, a moderate Democrat whose district overlaps with Ryan's, said the two had worked together in their effort to save a General Motors plant in Janesville. Although they weren't successful, Cullen said it wasn't because of a lack of effort from Ryan.

"I've known Paul Ryan for a long time. He's a serious guy," Cullen said. "I think the American people need more serious people in Washington and fewer bomb-throwers."

At least one person saw Ryan's potential more than 20 years ago. Sam Loizzo taught Ryan's government class in high school, and said it was apparent — even in 1988 — that Ryan was destined for great things.

"He was a great kid, a super student," Loizzo said. "He was definitely motivated to succeed."